The subjects were observed at the L’Enfant Plaza Metro Station, Orange Line platform videotaping features of the station and operations of the train. Once aboard an Orange Line train to Vienna they videotaped how patrons oriented themselves within the metro rail car” said a portion of the memo.

A rider noticed suspicious behavior by some men, took a photograph and reported the activity to Transit Police, according to Metro.

Metro said the internal memo was released as a standard procedure and was not meant for the public.

“As part of the routine follow-up, Transit Police issued a notice to all of its officers to be on the lookout for two individuals who were observed videotaping in Metrorail stations and on trains,” said Metro. “The incident was not meant to be elevated to a public alert level and was not meant to alarm anyone.”